Help, I think I have silverfish in my tank!

[Herndo]

I purchased 3 pieces of dead rock from LFS, I moved my tank this morning and put the dead rock at the bottom so I could seed it with the live rock on top. I rinsed off the dead rock and everything went smoothly.

But now I went to check on the tank and it's cleared up nicely but I saw three "bugs" on one of the pieces of dead rock. They look very much, almost identical, to the picture here.
http://www.doyourownpestcontrol.com/silverfish.jpg

Should I be concerned? Because I am.

[Herndo]

I couldn't stand it anymore so I broke out the sand vac. They came up easily and were actually already dead.

At first I thought I had finally found one of those unexpected suprises in my tank that I hear about all the time. Oh well. I don't think my live rock had any critters in it at all.